Endodontic System Research Articles

An evaluation of antibacterial efficacy of 3% sodium hypochlorite, high-frequency alternating current and 2% chlorhexidine on Enterococcus faecalis: An in vitro study.

Aim:The purpose of this study was to evaluate the antibacterial efficacy of 3% sodium hypochlorite (NaOCl), high-frequency alternating current (HFAC) (Endox Endodontic System), 2% chlorhexidine (CHX) in elimination of Enterococcus faecalis from experimentally infected root canals, in vitro.Materials and Methods:Eighty extracted, single rooted permanent upper anterior teeth were instrumented up to size 50, teeth were sterilized and inoculated with E. faecalis, subcultured in BHI broth which had its optical density adjusted to approximately 1.5Χ108 colony forming units (CFUs) ml-1 by comparing its turbidity to a McFarland 0.5 BaSO4 standard solution. After incubation for 24 h, the contaminated root canals were divided into four groups and subjected to action of NaOCl 3%, CHX 2%, and HFAC with physiological saline as a positive control. Sterile paper points were selected to take the sample of the bacteria and transferred to tubes containing 5ml of BHI broth and then incubated for 24 and 48 h, followed by agar plating of the resultant broth turbidity on Enterococcus confirmatory agar.Results:Data obtained were analyzed statistically for differences using chi-squared test, comparing different groups, with a significance level established at P<0.05 and 3% NaOCl showed no growth postoperatively, CHX and HFAC showed reduction of postoperative growth compared to physiological saline and, were statistically significant (P<0.05).Conclusion:In the present study, sodium hypochlorite, CHX, HFAC all were significantly effective in eliminating E. faecalis and sodium hypochlorite showed the maximum anti-bacterial activity against E. faecalis.

Alteration of Membrane Permeability of Bacteria and Yeast by High Frequency Alternating Current (HFAC)

Aims:Endox® Endodontic System (Endox) is used for endodontic treatment by a high frequency alternating current (HFAC). This device damaged the envelopes of spores and vegetative organisms. If the integrity of the envelope is compromised, the transit of compounds in the two directions is possible. This latter aspect was investigated here. Methods: The instrument delivered a 60ms pulse at a frequency 300 kHz, and power 800 KV/m. DNA transfer was verified using Escherichia coli K-12 strain carrying a non conjugative plasmid pBP517 (gyrA+) as donor and a rifampicin and nalidixic acid resistant recipient. 0.2 ml of mixture of donor and recipient strains in saline was exposed to HFAC and plated on selective media. Uptake of antimicrobials and a delay in re-growth was assessed exposing the strains to HFAC. Results:Plasmid transfer was detected under different experimental conditions. From 9 to 27 recombinants were found. Representative recombinants cured from plasmid showed the original phenotype. HFAC promoted the uptake of ineffective antibiotics, and induces a 1 h of delay in re-growth on the strains. Conclusions:Endox exhibited an effect on microrganisms which is reminiscent with that occuring in electroporation, but with a mode of action that saved materials and time.

Determination of the Performance of Various Root Canal Disinfection Methods after In Situ Carriage

The aim of this study was to compare the antimicrobial performance of the Endox Endodontic System (Lysis Srl, Nova Milanese, Italy), MTAD (Dentsply Tulsa Dental, Tulsa, OK), sodium hypochlorite (NaOCl), and HealOzone (Kavo, Biberach, Germany). Seventy instrumented and initially sterile roots with open accesses and containing a paper point were carried by one volunteer in the oral cavity for 1 week. After removal, samples were taken for microbiological analysis. The root canals were then disinfected with the Endox Endodontic System, MTAD, 3% NaOCl, or HealOzone, and, thereafter, samples were repeated for microbiological analysis. The roots were then sealed and incubated for a further week, after which bacterial growth was again determined. After disinfection, there was a significant decrease in the absolute bacterial count between each disinfection method and the positive control group. There was no statistically significant difference between the NaOCl, MTAD, and HealOzone groups. The Endox device showed the least antibacterial effect with significant differences to MTAD and HealOzone. Bacterial regrowth after 1 week of incubation was detected in all samples of the control group, whereas test groups showed several bacteria-free samples.

P605 Bactericidal effect and diminution of biofilm using Endox endodontic system

P605 Bactericidal effect and diminution of biofilm using Endox endodontic system

The effect of high‐frequency electrical pulses on organic tissue in root canals

To evaluate debris and smear layer scores after application of high-frequency electrical pulses produced by the Endox Endodontic System (Lysis Srl, Nova Milanese, Italy) on intact pulp tissue and organic and inorganic residues after endodontic instrumentation. The study comprised 75 teeth planned for extraction. The teeth were randomly divided into two groups (60 teeth) and a control group (15 teeth): group 1 (30 teeth) was not subjected to instrumentation; group 2 (30 teeth) was instrumented by Hero Shaper instruments and apical stops were prepared to size 40. Each group was subdivided into subgroups A and B (15 teeth); two electrical pulses were applied to subgroups 1A and 2A (one in the apical third and one in the middle third, respectively, at 3 and 6 mm from the root apices); four electrical pulses were applied to subgroups 1B and 2B (two in the apical third, two in the middle third). The control group (15 teeth) was prepared with Hero Shapers and irrigated with 5 mL of EDTA (10%) and 5 mL of 5% NaOCl at 50 degrees C but not subjected to the electrical pulse treatment. Roots were split longitudinally and canal walls were examined at 80x, 200x, 750x, 1500x and 15,000x magnifications, using a scanning electron microscope. Smear layer and debris scores were recorded at the 3 and 6 mm levels using a five-step scoring scale and a 200-microm grid. Means were tested for significance using the one-way anova model and the Bonferroni post-hoc test. The differences between groups were considered to be statistically significant when P < 0.05. The mean value for debris scores for the three groups varied from 1.80 (+/-0.77) to 4.50 (+/-0.68). The smear layer scores for group 2 and the control specimens varied from 2.00 (+/-0.91) to 2.33 (+/-0.99). A significant difference was found in mean debris scores at the 3 and 6 mm levels between the three groups (P < 0.001). The Bonferroni post-hoc test confirmed that the difference was due to group 1. In the two subgroups treated with four high-frequency pulses (1B and 2B) a substantial reduction in mean debris scores was found at the 3 and 6 mm level; subgroup 2B was practically free of organic residue. No significant differences for mean smear layer and debris scores were recorded between group 2 and the control group at the two levels; a significant difference was found only for mean smear layer scores at the 3 mm level between subgroup 2B and the control group (P < 0.05). The Endox device used with four electrical pulses had optimal efficacy when used after mechanical instrumentation. Traditional canal shaping and cleaning was essential to ensure an effective use of high-frequency electrical pulses in eliminating residues of pulp tissue and inorganic debris.

The endodontic system of equine cheek teeth: a reexamination of pulp horns and root canals in view of age-related physiological differences

The endodontic system of equine cheek teeth: a reexamination of pulp horns and root canals in view of age-related physiological differences

In vitro evaluation of the effects of the interaction between irrigating solutions, intracanal medication and Er:YAG laser in dentin permeability of the endodontic system.

The purpose of this study was to evaluate in vitro the effects of different associations between irrigating solutions (EDTA-T and citric acid), intracanal medicament (NDP), and Er:YAG laser irradiation on dentin permeability. Fifty-one extracted single-rooted teeth were instrumented and divided into seven groups. Groups GI and GII had final irrigation with a demineralizing solution only (EDTA-T and citric acid, respectively). Groups GIII and GIV had final irrigation with EDTA-T and citric acid, respectively, plus an association of irrigating solution and Er:YAG laser. Groups GV and GVI had final irrigation with EDTA-T and citric acid, respectively, plus an association of intracanal medication and Er:YAG laser. Group GVII (control group) had final irrigation with distilled water. All root canals were filled with NDP associated with rhodamine B dye. After the experimental period, the samples were transversely cut into six 2.0 mm thick slices for subsequent reading using the ImageLab software. Analysis of the results allowed us to conclude that there were statistically significant differences (p < 0.05) between the groups as to the penetration of the dye-intracanal medication solution. Groups III and IV presented smaller values of dentinal permeability when compared to the other groups. The best results were obtained with the interaction between a demineralizing irrigating solution and the association of intracanal medicament and laser Er:YAG (groups V and VI). In these groups the observed penetration of the intracanal medicament plus dye solution in the apical third was, on average, 29% greater than in the other groups.

Gutta percha obturation techniques

T h e most common cause of endodontic failure has been ascribed to incomplete obturation. Filling a root canal is intended to prevent microorganisms and toxins in the canal, as well as those present in the oral cavity, from passing along the root canal and moving out into the periradicular tissues. Matsumiya and Kitamura both demonstrated that bacteria remain in the deep portions of the endodontic system, even after chemical disinfectants. Healing of the periapical tissues occurs when the nutritional supply to the bacteria is stopped by the sealing properties of obturation. Unfortunately, the endodontic system is complex, including the accessory canals, anastamoses, and apical deltas. The inability to completely obliterate the irregularities of the endodontic system with a filling material and seal the apical delta foramen has been reported to account for nearly 60% of root-canal failures. Fluid percolation into the canal arises indirectly from the blood serum, water-soluble proteins, enzymes, and salts from both the apex and oral cavity. Once in the radicular space, those products undergo degradation and diffuse out to the periapical tissues and act as an irritant, which results in periapical inflammation. Bacteria will result in the producuon of toxic products in the root canal with periapical inflammation. In current endodontic treatment, is said that it is more important what comes out of the canal than what goes into So the emphasis seems to be placed more on cleaning and preparing the endodontic system than on filling it. This does not mean that obturation is less important; rather means that endodontic success depends on meticulous root-canal preparation. For a complete three-dimensional fill, proper instrumentation of the root canal makes a lot easier to facilitate. The objective of obturation of the radicular space is to fill the entire endodontic system and all of its complex anatomic pathways completely and densely with a nonirritating hermetic sealing agent(s), which results in a fluid-tight seal, especially at the apex, but also coronally (to prevent infection from the oral cavity). Success is dependent on the thoroughness of endodontic cavity design, shaping, and cleaning. The thoroughness of debridement and patency of the root-canal system facilitates its successful sealing in the three-dimensional phase. A three-dimensional fill is desired because it: 1) prevents percolation of the periapical exudate into the root-canal space (providing a culture medium for any residual bacteria); 2) prevents microorganisms from entering and reinfecting the root canal; and 3)

Evaluation of the anatomical alterations of lower molars mesial root’s apical third

The anatomical apex of the mesial root of the lower molars presents a morphological complexity related to the number and shape of the root canals as well as of the apical foramen and isthmus presence. The knowledge of the complexity of the endodontic system of the molar root area is essencial to select more carefully the best instrumentation and obturation technique, to obtain a more successful endodontic therapy.

Abstract of Current Literature

Effects of Aging on the Endodontic System, Reserve Crown, and Roots of Equine Mandibular Cheek Teeth by Khristina D. Kirkland, Gordon J. Baker, Sandra Manfra Marretta, Jo Ann C. Eurell, and John M. Losonsky

Identification of the Endodontic System in Carnassial and Canine Teeth in the Dog

A single radiograph of the endodontic system of a canine or carnassial tooth provides a two-dimensional image. Serial sectioning of these same teeth achieved a three-dimensional image, which may assist our understanding and therapies of these teeth. From the three dimensional images it was noted that the pulp chambers and root canals closely approximated the external topography of the teeth, with the exception of the palatal root of the maxillary fourth premolar tooth, and with this similarity becoming less obvious as the tooth matured. Developmental fissures were present in many teeth. Variations in the morphology of the endodontic system were noted in the distal root of the first mandibular molar tooth and the palatal root of the maxillary fourth premolar tooth. Accurate radiographs, with attention to these variations, are important determinants for successful endodontic therapy.

Effects of aging on the endodontic system, reserve crown, and roots of equine mandibular cheek teeth

Abstract Objective To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth. Design Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations. Sample Population 48 right hemi-mandibles from horses 2 to 9 years old. Procedure Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types. Results Permanent mandibular cheek teeth of the horse, at the time of eruption, consisted of an exposed crown and a reserve crown with a widely dilated apex. The endodontic system consisted of 5 or 6 pulp horns that connected to an expansive pulp in the reserve crown, which was confluent with the primordial pulp bulb surrounding the tooth’s apex. At the time of eruption, mandibular cheek teeth did not have a distinct pulp chamber, roots, or evidence of root formation. However, within 2 years after eruption, mesial and distal roots and a pulp chamber were present. A distinct pulp chamber, communicating with the pulp horns and both root pulp canals, was identifiable for 4 to 5 years from the time of root formation. The endodontic system of cheek teeth, 6 to 8 years after eruption, consisted of 2 unattached compartments, made up of a root canal, pulp chamber, and 2 or 3 pulp horns. Clinical Relevance The age-related morphologic changes in equine mandibular cheek teeth have important implications for application of endodontic therapy in horses. (Am J Vet Res 1996;57:31-38)

Coronal access of the Canine Dentition

Access preparation for endodontic treatment should be very exact, and knowledge of the anatomy of the teeth is a very important requirement for success. The use of radiographs is indispensable and should be used throughout endodontic treatment. The purpose of this paper is to discuss and illustrate correct coronal access for endodontic treatment in regard to the anatomy of the endodontic system. The most common teeth that require endodontic treatment are the canines, fourth maxillary premolars, first mandibular molars, incisors, and then the remaining premolars and molars. Special emphasis will be placed on coronal access of the canine, carnassial and incisor dentition.